Pulp splitter



l. H. WYNNE- PULP SPLITTER Jan. 27, 1959 Filed Feb. 5, 1957 2Sheets-Sheet 1 INVENTOR. [1P4 h! Wr/v/wr arm/7w! I. H. WYNNE PULPSPLITTER Jan. 27,1959

2 Sheets-Sheet Filed Feb. 5, 1957 IINVENTOR. In? H Wr/v/v' Z M m %We O 4j, I

United States Patent PULP SPLITTER Ira H. Wynne, San Francisco, Calif.,assignor to Reserve Mining Company, Silver Bay, Minn., a corporation ofMinnesota Application February 5, 1957, Serial No. 638,383

6 Claims. Cl. 209-284) The invention relates to a novel and improveddevice for the reception of a stream of particles, either dry or inliquid slurry or pulp, and for splitting said stream into two distinctlydiverging streams of identical physical characteristics, which streamscan be diverted to further processing devices.

By way of illustration, and not of limitation, the invention will bedescribed with reference to a step in the beneficiation of ores whereinground material is received from a grinding mill, screened to provideparticles less than a predetermined maximum size, and divided into twodiverging streams which proceed to further grinding and/or magneticseparation steps. The latter steps are, of course, utilizable only whena fraction of the ground ore has magnetic characteristics, as in thecase of the ferrous metal ore known as taconite.

In the treating of taconite, for example, the normal beneficiation stepsinclude crushing of the rock from the mine, followed by a number ofstages of coarse and fine grinding with intermediate separation stepsincluding liquid washing and magnetic separation. In a continuousprocess of thisnature it is desirable that the progressively refinedmaterial be advanced from each succeeding step to the next on conveyorswhich, have a downward gradient so that gravity is substituted for acertain proportion of the total power expenditure, thereby effecting asubstantial eventual saving in power costs.

Further, in such beneficiation process, the volumetric capacities ofindividual processing units diminishes with refinement of individualsteps, so that whereas a coarse crushing unit may turn out tons ofcrushed ore per minute, the output of a fine grinding mill or a magneticseparator may be measured in pounds per minute. Obviously therefore, tomaintain a process in which all units operate continuously, the materialbeing ground must be split at times into several channels, proceeding toidentical processing units. As a practical example the out put of asingle rod mill, in one typical grinding sequence, must be diverted to apair of ball mills, operating not in sequence but in parallel, in orderto keep the granular mixture or slurry moving. Rather than do this in aninterrupted batch process, it is highly desirable to split the materialcontinuously so as to provide two streams of identical analysis andparticle size, and when the stream is an aqueous pulp or slurry, twostreams of identical pulp density. This is desirable because commercialsuccess of the entire process is dependent to a great extent on carefulcontrol of all factors, including controlled homogeneity of the physicaland chemical characteristics of the material being processed.

While therefore the present invention will be described with occasionalreference to use in a process requiring grinding units in series, theapparatus is also applicable to other processes wherein comminutedmaterial is being divided into two streams of preferably identicalcharacteristics.

it An object of the invention is to provide novel, improved, andefiicient apparatus for splitting a moving stream of granular material,dry or in an aqueous pulp slurry, into two streams of similar physicalcharacteristics.

A further object of the invention is to provide apparatus of the typedefined in the last preceding paragraph wherein, in a continuouslydownwardly moving series of steps, the splitting is accomplished withonly a minor loss in elevation.

Other objects and advantages will be apparent from a study of thefollowing specification, in conjunction with the accompanying drawings,showing one embodiment of the invention, in which:

Fig. 1 is a view, partly in side elevation and partly in section,showing a pulp splitter embodying this invention.

Figs. 2, 3 and 4 are sectional views taken respectively on the lines 22,3-3, and 44 of Fig. 1.

Fig. 5 is a plan view of the screening material used in conjunction withthe invention.

The embodiment of the invention shown in the drawings is used inconjunction with a rod mill, the discharge end of which is indicated bythe broken lines 20 at the left of Fig. 1, the discharge spout of therod mill being shown at 21. The device which splits the pulp from therod mill comprises an inner cylinder 22 and an outer cylinder 23, theinner cylinder wall being formed from screen material 23a (Fig. 5) whichin the present instance has mesh openings approximately /8 by 4.

Mutual connection between these cylinders, and attachment of theassembly to the rod mill is effected asfollows. At the left end of thepulp splitter is a connecting collar comprising the two rings 24 and 25which are held rigidly together by a circumferential series of plates26. The ring 24 is attached to the ball mill by studs 27. The ring 25 iswelded to outer cylinder 23 and on the inner face of this ring 25 are aseries of lugs 28 which support a collar 29 to which the inner cylinder22 is attached. The right end of cylinder 22 is similarly attached to acollar 30 which has an outturned flange 31 connected by bolts 33 to aring 32 carried by cylinder 23. It will be apparent that the pulpsplitter can be separated from the rod mill by removing the nuts fromstuds 27, and that the inner screen cylinder 22 can be removed from theouter cylinder 23 by removing the nuts from bolts 33 and withdrawing theinner cylinder laterally to the right.

Along the inner periphery of cylinder 22 there are arranged a series ofhelical ribs projecting inwardly and arranged in compound threadfashion, parts of three flights being shown respectively at 34, 35 and36. It will be noted that the integral continuation of flight 35, at theright lower end of Fig. 1, appears again at the lower left of center.The pulp splitter is fixedly attached to the rod mill and rotates withit, and consequently the ground material discharged from the rod mill inan aqueous slurry, proceeds to the right over spout 21 (Fig. 1) andfalls 011 the screen wall 22, whence it is impelled to the right byscrew flight ribs 34, 35 and 36. In its passage the smaller lumps andparticles fall through the screen wall of cylinder 22 into the lowerpart of the annular space between cylinders 22 and 23. The particleswhich are too large to pass through the screen are discharged at theright end and may be recirculated to the rod mill.

Centrally disposed around the outer cylindrical wall 23 is an annulus orchannel 37 having two radially projecting parallel walls 38 and 39 and aperipheral wall 40. This annular channel is divided into a plurality ofsegments by a respective plurality of partitions 41 which extendcompletely across the channel, and which are angularly inclined to sidewalls 38 and 39, the angle of inclination being alternately reversed inprogressive sequence along the channel as best seen in. Fig. 4, for apurpose soon to appear.

series of peripheral ports 44 (Fig. 3), each port communicating with arespective channel segment, so that as the pulp splitter rotates, thesludge in the annular space between cylinders 22 and 23 fallsprogressively through each successive port 44 as it passes its lowermostposition, and enters the respective segment communicating with each saidsuccessive port.

The parallel side walls 38 and 39 are provided with discharge apertures45, 46, 47, 48, 49, 50, etc. (Fig. 3), there being one aperture to eachsegment, and the apertures being alternately staggered, right and leftin sequence, so that apertures 45, 47 and 49 are in one wall and 46, 48,and 50 in the other wall. For this reason the pulp slurry in alternatesegments will discharge in alternate directions as each segment reachesbottom center. While this would operate quite satisfactorily even ifpartitions 41 were disposed in planes coincident with the axis ofrotation, they are inclined to promote discharge flow through theopenings between them.

As seen in Fig. 1 there is shown means providing a pair of troughs 53and 54 which proceed to a respective pair of further processing units,in this case a pair of ball mills, for finer grinding of the pulp. Itwill be obvious that alternating increments of the pulp are divertedright and left so rapidly that the flow is practically continuous intoeach trough and the physical and chemical characteristics of the splitstreams are uniform. Troughs 53 and 54 are shown only in section sincefurther illustration thereof is unnecessary, and the arrangement ofunits with which these troughs are connected is a matter of convenienceof unit installation.

What I claim is:

1. Means for receiving a flow of ground material of varying particlesizes and splitting at least a portion of said flow of material into twodistinct divergent streams, said means comprising a cylinder into whichsaid material is delivered, said cylinder being rotatable on asubstantially horizontal axis, an annular peripheral channel supportedon the outer wall of the cylinder and bounded by a pair of outwardlyprojecting side walls, and a bottom wall carried thereby enclosing thespace between the side walls, a plurality of partitions extending acrosssaid channel at respectively spaced locations whereby to divide saidchannel into'a plurality of segments, said cylinder wall being providedwith openings, one opening in registry with each segment, said sidewalls being provided with discharge apertures, one aperture to eachsegment, the apertures being alternately staggered, right and left insequence, whereby, when said cylinder is rotated, material falls bygravity into said segmentsin turn, and therefrom out of said staggeredapertures in alternate sequence.

2. Means for receiving a ground agglomerate of varying particle sizesfrom a processing device and splitting at least a portion of saidagglomerate into two distinct streams diverging to respective furtherprocessing devices, said means comprising inner and outer coaxialcylinders fixed with respect to each other and rotatable on their commonhorizontal axis, said inner cylinder having a mesh screen wall portion,means for moving said agglomerate from one end of said inner cylindertowards the other during rotation of said cylinders whereby at least apart of said agglomerate falls through said mesh screen into the spacebetween the cylinders, an annular peripheral channel supported on thewall of the outer cylinder and bounded by a pair of outwardly projectingparallel side walls, and a bottom wall carried thereby, a plurality ofpartitions extending across said channel at respectively spacedlocations whereby to divide said channel into a.

plurality of segments, said outer cylinder wall being provided with aring of spaced ports, one port in registry with each segment, saidparallel side walls being provided with.dischargeapertures, one apertureto each segment, the apertures being alternately staggered, right andleft in sequence, whereby, when said cylinders are rotated, screenedmaterial falls by gravity into said segments in turn, and therefrom outof said staggered apertures in alternate sequence.

3. Means for receiving a ground agglomerate of vary ing particle sizesfrom a processing device and splitting at least a portion of saidagglomerate into two distinct streams diverging to respective furtherprocessing devices,

said means comprising inner and outer coaxial cylindersfixed withrespect to each other and rotatable on their common horizontal axis,said inner cylinder having a mesh screen wall portion, means for movingsaid agglomerate from one end of said inner cylinder towards the otherduring rotation of said cylinders whereby at least a part of saidagglomerate falls through said mesh screen into the space between thecylinders, an annular peripheral channel supported on the wall of theouter cylinder and bounded by apair of outwardly projecting parallelside walls, and a bottom wall carried thereby, a plurality of partitionsextending across said channel at respectively spaced locations wherebyto divide said channel into a plurality of segments, saidpartitions-bei'ng angularly inclined to said parallel sidewalls, saidouter: cylinder wall being provided with a ring of spaced ports,

one port in registry with each segment, said parallel sidewalls beingprovided with discharge apertures, one aperture to each segment, theapertures being alternately staggered, right and left in sequence,whereby, when said cylinders are rotated, screened material falls bygravityinto said segments-in turn, and therefrom alternately out of saidstaggered apertures in turn.

4. Means for receiving a ground agglomerates of varying particle sizesfrom a processing device and splitting at least a portion of saidagglomerate intotwo distinct streams divergingto respective furtherprocessing devices,

said means comprising inner and outer coaxial cylinders fixed withrespect to each other and rotatable on their common horizontal axis,said inner cylinder having a mesh screen wall portion, means for movingsaid ag glomerate from one end of said inner cylinder towards the otherduring rotation of said cylinders whereby at least a part ofsaid-agglomerate falls through saidmeshv plurality of partitionsextending across said channel at respectively spaced locations whereby.to divide said" channel into a plurality of segments, said partitionsbeing angularly inclined to said parallel sidewalls, theangle ofinclination being alternately reversed in progressive sequence along thechannel, said outer cylinder wall being:

provided witha ring of spaced ports, one port in registry with eachsegment, said parallel side walls being provided with dischargeapertures, one aperture to each-Z segment, the apertures beingalternately staggered, right:

and left in sequence, whereby, whensaid cylinders are rotated, screenedmaterial falls by gravity into said segments in turn, and therefromalternately out of'said staggered apertures in turn.

5. Means for receivinga ground agglomerate of varying particle sizesfrom a processing device and splitting at least a portion of saidagglomerate into two distinct streams diverging to respective furtherprocessing devices,

said means comprising inner and outer coaxial cylinders fixed withrespect to each other and rotatable on their common horizontal axis,said inner cylinder having a mesh screen wall portion, means for movingsaid agglomerate from one end of said inner cylinder towards the otherduring rotation of said cylinders whereby atleast a part of saidagglomerate falls through said mesh inner periphery of said innercylinder, an annular peripheral channel supported on-thewallof the-outercylinder and bounded by a pair of outwardly projecting parallel sidewalls, and a bottom wall carried thereby, a plurality of partitionsextending across said channel at respectively spaced locations wherebyto divide said channel into a plurality of segments, said outer cylinderwall being provided with a ring of spaced ports, one port in registrywith each segment, said parallel side walls being provided withdischarge apertures, one aperture to each segment, the apertures beingalternately staggered, right and left in sequence, whereby, when saidcylinders are rotated, screened material falls by gravity into saidsegments in turn, and therefrom alternately out of said staggeredapertures in turn.

6. Means for receiving a ground agglomerate of varying particle sizesfrom a processing device and splitting at least a portion of saidagglomerate into two distinct streams diverging to respective furtherprocessing devices, said means comprising inner and outer coaxialcylinders fixed with respect to each other and rotatable on their commonhorizontal axis,- said inner cylinder having a 20 mesh screen wallportion, means for moving said agglomerate from one end of said innercylinder towards the other during rotation of said cylinders whereby atleast a part of said agglomerate falls through said mesh screen into thespace between the cylinders, an annular peripheral channel supported onthe wall of the outer cylinder and bounded by a pair of outwardlyprojecting side walls, and a bottom wall carried thereby, a plurality ofpartitions extending across said channel at respectively spacedlocations whereby to divide said channel into a plurality of segments,said outer cylinder wall being pro vided with a ring of spaced ports,one port in registry with each segment, said side walls being providedwith discharge apertures, one aperture to each segment, the aperturesbeing alternately staggered, right and left in sequence, whereby, whensaid cylinders are rotated, screened material falls by gravity into saidsegments in turn, and therefrom alternately out of said staggeredapertures in turn, and respective receiving means under each said sidewall wherein to receive material discharged from said apertures.

References Cited in the file of this patent UNITED STATES PATENTS1,387,238 Cave Aug. 9, 1921 FOREIGN PATENTS 10,824 Great Britain May 7,1909

